The present invention relates to electro cauterization, particularly to a micromachined electrical cauterizer, and more particularly to a microfabricated cauterizer which can be used in conjunction with irrigation and suction, tissue sampling, and drug delivery operations utilizing a single microtool, as well as being utilized as a biosensor.
In open surgery and laparoscopic surgery, it is very important to achieve sufficient homeostasis. This not only prevents the patient from bleeding extensively but also allows the surgeon to better visualize the operation. Heomostasis can be achieved by either high frequency (HF) current, laser, or simply clipping. HF current is most commonly used to energetically induce a method of achieving heomostasis and is generally inexpensive and reliable. Furthermore, the more focused the HF current the less traumatic it is for the patient and which can be accomplished by closer placed bipolar electrodes. It is also intuitively true that the sharper the tool the less bleeding due to a small incision. One of the problems for laparoscopic surgery is the constant removal of tools. By miniaturizing and integrating multi-functional devices, systems can be built that require fewer tool exchanges which means shorter surgery duration.
With bulk silicon micromachining, one is able to generate microgrippers, such as described and claimed in copending U.S. application Ser. No. 08/446,146, filed May 22, 1995, entitled "Microfabricated Therapeutic Actuator Mechanisms", now U.S. Pat. No. 5,645,564 issued Jul. 8, 1997; and mircrobiopsy devices having sharp knife edges at the intersection of the crystalline planes of silicon by anisotropic etching, such as described and claimed in copending U.S. application Ser. No. 08/887,780, filed Jul. 3, 1997, entitled "Microbiopsy/Precision Cutting Devices". Furthermore, suction and/or irrigation is often necessary besides the pure dissecting of tissue and/or depositing of medicines.
The present invention at least partially overcomes the above-mentioned tool exchange problems, and by appropriate microfabrication enable the conjunction of several operational procedures into one tool, thus simplifying surgical procedures. By micromachining of silicon, now a well established technique, in conjunction with well established photolithographic and material deposition techniques, many of the necessary surgical functions or procedures mentioned above can be carried out utilizing a single tool. This invention provides such a tool by combining electrocauterizing with drug delivery, biosensors, and microactuation. For example microbiopsy can be carried out in conjunction with sampling of tissue beneath the surface followed by cauterization of the sample area and depositing of a drug or medication to eliminate infection or for other purposes. Also, the electrodes for cauterization can be used as sensing devices to probe the electrical resistance in contact and discriminate between tissue/clots and provide feedback to the operator. Thus, the present invention involves a microelectrical cauterizing tool made by silicon micromachining techniques in conjunction with photolithography and material deposition techniques, which can be used along or in conjunction with micro-procedures.